Oihgtjit oloseb foe burglar alarms



UNITED STATES WILLIAM C. FISHER, OF BOSTON, MASSACHUSETTS ASSIGNOR OFONEHALF PATENT OFFIC TO CHARLES E. AND FRANK FULLER, OF SAME PLACE.

CIRCUIT-CLOSER FOR BURGLAR-ALARMS.

SPECIFICATION formingpart of Letters Patent No. 279,483, dated June 12,1883.

ApplicationfiledDecemberQ'i,IBFZ. (Nommleh) To all whom it may concern:

Be it known that 1, WILLIAM C. FISHER, of Boston, county of Suffolk,State of Massachusetts, have invented an Improvement in Gircuit-Olosersfor Burglar-Alarms, of which the following description, in connectionwiththe accompanying drawings, is a specification,

like letters 011 the drawings representing like parts.

My invention relates to a circuit-closer for burglar-alarms, it beingintended to be mount ed in a window-frame and operated by the movementof the sashes to close an electric circuit, and thus sound an alarm whenthe sashes are moved. r

The apparatus consists, essentially, of a frame-plate mountedhorizontally in the window-frame and occupying a portion of the guidesfor both sashes, it being preferably located at .the point where themeeting-rails of the sashes remain when the window is wholly closed. Thesaid plate is provided with two movable keys, having projections thatare engaged by the sashes when moved to open the window, thus pressingthe said keys into con tact with a cooperating yielding contact point orspring mounted on the said frame-pl ate, but insulated therefrom, thesaid spring forming one terminal, and the frame-plate, with its keys,forming the other terminal of the circuit to be closed. By mounting theapparatus horizontally its construction is simplified, and the spaceoccupied by it, and consequently the amount of wood that has to be cutaway from 3 5 the window-frame to receive it, is reduced.

Figure 1 is a horizontal section of a portion of a window frameand'sashes provided with a circuit-closer embodying this invention; andFigs. 2 and 3, front and rear elevations, re-

- 4o spectively, of the circuit-closer detached.

The circuit-closer consists, essentially, of a metal plate, a, providedon its rear side with lugs I), between which are mounted the movablekeys 0 0, provided with projections 0 extending through openings 2 inthe'plate a be yond the front face thereof, as shown in Fig.

1. The said keys are in this instance shown as pivoted upon spindles (I,mounted in the lugs b of the frame-plate, and are acted upon by springse, tending to keep the projections c of the keys 0 c forced out throughthe openings 2 in the plate a, as shown in Fig. 1, but yielding topermit the said keys to be turned back ontheir pivots, as shown indotted lines at the right of Fig. 1, when the sash is moved so as tobear against the projecting end of the key.

The. keys 0 c are shown as in metallic connection with the plate a, andform one terminal of the circuit to be closed, the other terminal beingconnected with the co-operating contactspring f, mounted on a block, 72,of insulating material received between the lugs b and secured to theplate a, as by screwi. The lugs 11, which in this instance serve to holdthe pivot-spindles (l of the movable keys, are intended specially toreceive and hold rigidly between them the block 71 of insulatingmaterial, on which the contact-point f, co-operating with the said keys,is mounted, the said lugs, together with the plate a, forming a rigidand sufficient frame-work for maintaining the cooperating parts of thecircuit-closer in the proper relative position.

In operati on the apparatus is connected with the frame of thewindow, asshown in Fig. 1, 75 it being cut away to receive lugs b and afford spacefor the movement of the key a at the rear of plate a, which is flushwith. the frame and connected therewith, by screws in the usual manner,it being preferably located at the point occupied by the meeting-railsmn of the sashes when the window is closed. The sashes are cut-away orrecessed, as shown at 3, to permit the keys 0 c to remain in theirnormal position when the window is closed, and the 85 said recess 8 maybe extended any desired dis tance up or down the sash to permit it to beopen a certain distance without operating the circuit-closer.. When,however, the sash is moved so that the recessed portion is carried gobeyond the projection of the key 0 or c, the unrecessed portion of thesash, acting on the I said projection, forces the key back, as shown indotted lines, Fig. 1, making the connection between the said key and thespringf. It 9 5" will be seen that the movement of either key closes thesame circuit, and a very simple compact apparatus is afforded forindicating the movements of both sashes.

construction of the circuit-closer herein shown, the essential featureofwhieh consists in mounting the keys in a plate transversely to thewindow-fran1e, thus :torming a compact device for operation with bothsashes.

1. The herein-described circuit-closer for burg]analarms, consisting ofthe flat framepla-te adapted to be mounted in a windowframe transverselyto the sash-guides, and provided with openings near its ends, one ineach sash-guide, combined with the independentlymovablc keys havingn'ojeetions extending through the said openings and eo-eperatingcontact-points normally insulated from the said keys, substantially asand for the purpose described.

